Thermostatically operated electrical device



June 18, 1935. E KLAHN 2,005,549

THERMOSTATICALLY OPERATED ELECTRICAL DEVICE Original Filed July 26, 1926 2 Sheets-Sheet l Elvwenfoc 135;; Z Q QHOWM; Z

June 18, 1935. E. KLAHN THERMOSTATICALLY OPERATED ELECTRICAL DEVICE 1926 2 Sheets-Sheet 2 Original Filed July 26' Patented June 18, 1935 I UNITED STATES PATENT OFFICE THERMOSTATICALLY OPERATED ELEC- TRICAL DEVICE Emil Klahn, New Vernon, N. J.

Application July 26, 1926, Serial No. 124,917 Renewed November 15, 1934 4 Claims. (Cl. 200-122) This invention relates to thermostatically opto render it possible to obtain alternate flashes erated switches and signalling apparatus operfrom ordinary electric bulbs mounted therein, ated thereby and has for its principal objects i. e. the plug 8 is provided with a central aperthe provision of thermostatic switches which are ture ID in which is positioned a metallic sleeve a certain in operation, compact, durable and sim- H, the latter being provided with a terminal .3 ple of construction, as well as the utilization of flange II at one end and being threaded at a thermostatic switch to intermittently operate its upper end and provided with a terminal nut a signalling apparatus. Further objects of the l2 which is adapted to abut against a shoulder invention are the construction of a thermostatic c in the upper end of said recess ID. A positive 10 switch without employing therein a bi-metallic binding post or bolt l3, having a threaded upper 1 thermostatic metal element. Various other obend l3, projects centrally through the central jects and advantages are hereinafter specified. bore of the porcelain plug 8 and is threaded My invention is fully set forth in the followinto the threaded sleeve M of a positive U- ing description and drawings forming a part shaped spring contact member i5. Still another there f, in which latter. threaded metallic socket l6 serves as the other 1:,

'Figure 1 is a central longitudinal section, ceror negative C ntact for the filament of a lamp, tain parts thereof being shown in elevation, of for example, a red electric bulb r, when the a signal employing two flashing lamps of differlatter is mounted in said socket, as shown. The ent colors; Socket I6 is secured by means of an integral Fig. 1A is a diagrammatic view of the elecstrip 16 to a bolt I! that is mounted in the 20 trical circuit of the construction shown in supplemental porcelain plug I8 and the exten- Fig. 1; sion l9 of said socket is in snug engagement Fig. 2 is a transverse section on the line 2-2 with the upper end of the sleeve 9 which in of Fig. 1; turn is in electrical communication through the g. 3 is a t p plan view of the lower portion post 5' with the negative lead I). 25 of the device with the socket portions removed; A second U-shaped spring contact member 20 and is also supported by said post l3, but is insu- Fig. 4 is a bottom plan view of the base. lated therefrom by a sleeve 2| which surrounds Referring to Figs. 1 to 4 of the drawings, the the greater portion of the post l3 and is also inreference numeral I designates an apertured sulated from the contact l5 by the insulating 30' base plate to which is secured an apertured gasket 22. The inner end 20 of said contact 20 panel I' of insulation material that bridges the is oifset obliquely to cause it to contact with aperture a. Distant from the recess is a socket the conductor strip 23, the opposite end of member f a two-piece plug 2 adapted to rewhich latter engages the nut 12 and is thereby ceive a blade member such as is commonly sein communication, through the metallic tube 35 cured to the end of a lamp cord whereby cur- II, with the terminal ring 24 of a positive conrent is fed from any suitable source of supply tact member 24 carried by a positive binding into the lead wires, b, b of the device. post 25. A threaded metal socket 26 is also An outer metal shell 3 is supported on said secured to the plug l8 by means of a bolt 21 40 panel I and the same envelopes a threaded and said socket serves asa negative terminal for -10 inner metal socket member 4 which is mounted the filament of a lamp, for example, a blue elecon posts 5, 5'. A thimble 6 of hard rubber trio bulb y. r other insulation material is threaded onto A thermostatic switch member serves to either the outside of said socket 4 and projects bealternately illuminate the respectiveblue and tween the latter and the inside of the shell 3 red lamps or, if the double socket 9 is removed 4! and at the same time its upper end serves as and an ordinary electric bulb inserted in the an abutment to engage the end of the porcelain socket 9, to periodically illuminate such bulb. shell I of a two-Way socket member, in which This thermostatic switch comprises preferably latter is secured a central porcelain plug meman arc-shaped heat-responsive element 30 of ber B, carrying a threaded metal sleeve 9 that well known bi-metallic thermostatic metal and is adapted to co-operate with the threaded metal comprising strips of dissimilar material as an socket 4, and to receive current conducted to outer strip m of steel having a low index of exsaid sOcket 4 through the post 5 which serves pansion and an inner strip of brass n having a as a binding post for the negative current lead rlatively high index of expansion. A bracket 7 b. Said two-way socket is specially constructed 3| has its vertical arm bra-13 s? or riveted to snd element 30 at a point adjacent to the center of the arc and is in turn secured by a post 32v to the panel I. A snapping membrane element 33. of ribbon steel, is mounted on the free ends of element 30 and spans the intervening space. Said spring is normally deformed, preferably by centrally crimping the same so that the natural position assumed by the spring when the element 30 is cold in the absence of a stop, would substantially correspond to the dash line position of Fig. 2. Said membrane 33 is preferably provided with precious metal contact points 34, 34'.

As shown,- the ends of said membrane element 33 are not rigidly connected to the respective ends of the arc-shaped member 30, but merely project into slots formed in the latter, whereby relative movement of the ends of said membrane element 33, with respect to the ends of the arc-shaped element 30 in which they are mounted, is permitted, thus avoiding fatigue and crystallization of the membrane element adjacent its ends. However, as hereinafter. described with reference to the construction shown in Fig. 8, the membrane element may be integral with the heat-responsive element ,though the construction shown in Fig. 2 is for many purposes preferable. i

Suitable heating means, for example, coils 35, 35' of bare nichrome wire are wound aroundthe respective arms of the heat-responsive element 30, the same'being separated from actual contact therewith by means of mica separators 35. The respective ends of said heating coil are connected to binding posts 31, 38, the former binding post supporting a spring contact strip 39 that is adapted to normally engage the contact post I3, and the latter binding post 38 carrying a contact 38' which is adapted to periodically engage with the stop or contact 34. As shown in Fig. 1A, the filament of the red lamp is in series with the coils 35, 35' and consequently, when the switch is in the position shown in this figure, the current will pass through the coils and through the filament of the red lamp, thus illuminating the latter, but when the membrane member is in engagement with the stop 40, the current will pass through the filament of the blue lamp, thus illuminating the same and no current will flow through the filament of the red lamp or the heating coils 35 and 35'. The initial position of the switch when cold is that shown in Fig. 1A and as the heatresponsive arms are heated by the coils 35 and 35', the said arms will expand and the snapping membrane element will suddenly snap into the position wherein the contact point 34 thereof will engage the contact 40, in which position the circuit, through the coils 35, 35' will be broken thereupon the arms will commence to cool and consequently contract, and as this progresses, the critical point will be reached wherein the membrane 33 will suddenly snap from its engagement with the contact 40 and suddenly engage the contact 38.

Theposition of the contact 38' should preferably be such that when the armsof the heatresponsive element 30 gradually heat up and move slowly outwardly, the contact point 34, carried by the membrane 33, will snap away from the contact 38', thus making a sudden break between the contacts 34 and 38' and a sudden make between the contacts 34' and $3. As the arms cool down while the circuit is closed through the contacts 363' and 49. the latter being connected through the strip 4| with the binding post 25, the contact 34' will in turn suddenly snap out of engagementwith the contact 40 and the contact 34 will snap into engagement with the contact 38'.

In the construction shownin Figs. 1 to 4 inclusive the membrane member 33, as shown, is deformed by crimping or distorting the same so that the natural position of such membrane, if unconfined, would substantially correspond to the dash line position shown in Fig. 2 and consequently, when the membrane is forced in the position shown in full lines in Fig. 2 as a result of the pressure of the cold thermostatic arms of the thermostatic member 30, such membrane will be in an unnatural or strained position and upon the least provocation, such as occurs when the pressure of such arms becomes relieved upon the heating of the same, the contact 34 will tend to 'snap away from the contact 38 and consequently snap into engagement with the contact 40 simply by virtue of the fact that both the contact 38' and the contact 40 are at the edges of the snapping or critical zone and the slightest cooling of the thermostatic arms beyond the point where they exert suflicient pressure to hold the contact 34' in engagement with the contact 40 will result in a sudden movement of the membrane and snapping re-engagement'of the contact 34 with the contact 38'.

The membrane member shown in Figs. 1 to 3 is preferably deformed by means of the deforming clamps, such as disclosed in my co-pending application, filed February 25, 1926, Serial No. 90,521 or in any other desired manner, no claim beingmade herein to such deforming clamps as such.

The curvilinear contact strip or member 24? is preferably arranged so that a portion thereof normally extends in close proximity, either Just above or just below, the bottom of the shell 4 and consequently if, in lieu of the two-way socket member I, an ordinary light bulb is threaded into the socket 4, it can be inserted sufliciently far therein to eflect the slight buckling of the strip 24' with the result that it will directly engage the said shell which latter is in circuit with the binding post 5. Accordingly, in lieu of the alternate periodic extinguishment and illumination of such lamp in consonance with the movements of the membrane 33, the filament thereof will alternately glow brightly when the contacts 34' and 40 are in engagement with each other and be dimmed, but not extinguished, when the contacts 34 and 38' are in engagement, since in the latter case the resistances 35, 35' will be cut into the circuit of the filament. Obviously, such a construction affords a convenient arrangement for automatically producing a high-low eifect and of course, if desired, a plurality of lamps in parallel can be arranged in the circuit with such resistances in lieu of a single lamp so as to exaggerate the flickering effect thus produced.

Having thus described by invention, what I claim and desire to obtain by United States Letters Patent is:

1. The combination comprising an electric socket an electric signalling device mounted in said socket, a snapping thermostatic switch including a bi-metallic thermostatic element, and a resistance element for periodically supplying heat to the thermostatic element of the switch. the switch being adapted when the signalling device is in one position to periodically efiect the operation of said signalling device when the circuit through the signalling device circuit is closed, and means adapted, when said signalling device is adjusted to another position to prevent the complete extinguishment thereof at any time while said circuit is closed and to effect the partial dimming of the signal emitted by said signalling device periodically in response to the movements of the switch.

2. The combination comprising an electric socket, an electric signalling device mounted in said socket, a snapping thermostatic switch for controlling the circuit of said signalling device, said switch including a bi-metallic thermostatic element, an electric resistance directly associated with said thermostatic" element for periodically heating the thermostatic element of the switch and means for periodically connecting the resistance element into the circuit and producing an alternate intensive emission and dimming of the signal without breaking the circuit through the signalling device.

3. An electric light fixture having a multi-way socket, a snapping thermostatic switch associated with said socket, said switch including a bimetallic thermostatic element and a resistanceheating element, the latter being adapted to be periodically connected with the filament circuit of a lamp inserted in said socket in response to the snapping movements of said switch, means responsive to the movement of said switch for alternately opening and closing the circuit through different lamps mounted in said multiway socket whereby a multi-colored flashing effeet can be obtained.

4. The combination comprising an electric fixture provided with a multi-way socket, a plurality of electric signalling devices mounted in said socket, a snapping thermostatic switch associated with said socket, the same including a bi-metallic thermostatic element, a circuit common to at least two of said signalling devices that are mounted in said socket, the flow of current through said circuit being controlled by said switch and a resistance-heating element also interposed in said circuit and adapted to peeriodically heat the bi-metallic thermostatic element in said switch.

. EMIL KLAHN. 

